We tend to forget the side-benefit of our involvement in Iraq - and that is the drastic reduction of terrorist activity in Israel.
Since the fall of Iraq and the removal of Saddam Hussein, the terrorist activity in Israel has almost ceased. Maybe this is due to the end of payments to the families of the suicide bombers by the Hussein regime, the presence of the US military in Iraq or the terrorists' focus being redirected toward the US troops in Iraq, the beneficiaries would seem to be, in some measure, the state of Israel.
Think about the last time you saw or heard a news report about a terrorist act - marketplace or bus suicide bombing - since the fall of Saddam Hussein. Before the US went into Iraq, it seemed like a weekly, if not a daily, occurrence.
If you have not read Victor David Hanson's article, I recommend it: What happened to Iraq?